Starter for vapor electric devices.



P. H. THOMAS.

STARTER FOR VAPOR ELECTRIC DEVICES. APPLICATION man APR. 25. 1904.

1,144,396@ Patented June 29, 1915.

citizen of the United States,

rs rnwr men.

PERCY H. THOMAS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY,

A. CORPORATION OF NEW JERSEY.

STARTER FOR VAPOR ELECTRIC DEVICES.

To all whom it may concern:

Be it known that I, PERCY H. THOMAS, a and resident of East Orange, countyo-f Essex, State of New Jersey, have invented certain new and useful Improvements in Starters for Vapor Electric Devices, of which the following is a specification.-

It is found in operating vapor lamps and converters that it is possible to maintain a flow of current between electrodes through a portion of the vapor much more easily when current has once been established than before its establishment. This may result from the action of residual gas found in the container which hasto be pierced by the electric particles forming the current before the elec-- trodes can be bridged. Once a current of definite value is'established, it has a definite voltage which drops continuously from one electrode to the other. Suppose this vapor column carrying current to be in parallel within the chamber with a conducting filament; the current has the choice of two paths, one through the filament and one through the vapor. It will ordinarily divide between the two, enough current flowing through the filament to maintainthe voltage drop the same as that through the vapor. If we assume that, under. the described conditions, the current decreases in the divided circuit, the voltage of the vapor will increase, causing a greater proportion of the current to pass through the filament. .At a

certain point in the general decrease: of our-- rent, the voltage of the vapor w1ll rise very all the current passes through rapidly until On the other hand,

the filament.

the vapor causing a lowering of its voltage and Withdrawing current from the filament. The fact that the voltage of the filament, under increments of current, increases more rapidly than the voltage of the vapor under similar conditions accounts for these actions.

Specification of Letters Patent.

if we increase the current through the divided cir- "cuit, a greater proportion will fiow'through Patented June 29, 1915.

Application :filed April 25, 1904. Serial N 0. 204,712.

and the end'of the filament the voltage drop is greater than the normal drop through the vapor when the apparatus has been fully started into operation. Under these conditions, the point at which the current enters the filament from the vapor will be determined by the relative voltages as above described, but this point will creep along the filament toward the positive electrode, since by so doing the total resistance of the circuit is lessened. This movement of the point of entrance will finally extend to the positive electrode itself, provided the filament is of proper resistance taken in connection with the value ofth'e current employed and the vapor conditions, although the current might not be able to pass at once from the positive electrode to the negative electrode'through the vapor without the presence of the filament. I

My invention is illustrated in the accompanying drawings, in which Figures 1, 2, 3, 4 and 5 represent different embodiments of the invention herein described and claimed.

In the first figure of the drawing, 1 is a so container of a' gas or vapor electric appa ratus and is provided with a positive electrode, 2, and a negative electrode, 3, joined, respectively, to lead-wires, 4 and 5. The negative electrode may be of mercury and may be provided with a projecting point,

6, of platinum or other suitable material which may be supported upon the inner end of the lead-wire 5. Extending through the container 1 from the positive electrode 2 into contact with the point 6 or with the negative electrode 3 is a carbon filament, 7,

forming a continuous conductor between the electrodes 2 and 3. When current is turned on and the container is slightly jarred so as to break contact between the lower end of the filament and the point 6 or the electrode 3, it will flow through the filament 7 and break down the initial resistance at the negative electrode. If the resistances are properly proportioned, a portion of the current will'pass through the vapor between the negative electrode and a point on the filament more or less close to the negative electrode. This point, will gradually recede from the negative electrode until it extends to the positive electrode 2 whereupon the v under the normal condition of the lamp, in

which case the spectrum given oil? by the luminous vapor proper will be supplemented by the light from the filament, which is'a desirable condition. I

In Fig. 2, the conditions are generally similar, but in this instance the lower end of the filament is not normally in contact with the negative electrode, but is placed in such proximity thereto that it can readily be jarred into contact therewith after which it will resume its normal position away 'from the electrode. The operation is the same as before.

In Fig. 3, the lower end of the filament has attached to it a piece, 8, of magnetic material, the same being capable of being acted upon by a magnet, 9, for separating the filament and the piece 8 from contact with the negative electrode, thereby starting the fiow of current in the vapor. In this instance the filament 7, instead of being connected directly to the positive electrode 2 is connected to a lead-wire, 10, extending through the upper wall of the container, while a resistance, 11, is inserted between the lead-wire 10 and the lead-wire l. It is found that when the creeping up of the current has proceeded nearly to the positive electrode it will pass directly through the vapor from the said positive electrode to the negative electrode.

In Fig. 4, the filament is joined to the lead-wire 4 inside the container but above the electrode 2.

Fig. 5 shows two positive electrodes, 12

New York, and

ally, yet they are particularly recommended for starting vapor lamps.

The arrangement wherein a plurality of positive electrodes is shown, one of which is connected with a filament extending through a portion of the container is useful in connection with alternating current apparatus wherein impulses of different phase are impressed upon the" several positive electrodes.

-In case the filament is so proportioned as to its resistance that the current taken by the filament in the operative condition of the lamp is sufi'icient to heat it to the light giving point, either a portion or the whole of the filament, it is clear that the well known spectrum of mercury vapor will be supplemented by the light given of]? from the filament. This may be an advantageous adjustment.

I claim as my invention:

In-a vapor lamp containing a filament, the method of of the vapor, which consists in. so proportioning the resistance of the filament to that of the vapor that the current taken by the 'filament under operating conditions shall bring a portion or the whole of .the filament to the light-giving point.

Signed at New York, in the county of State of New York, this A. D. 1904.

PERCY H. THOMAS.

Witnesses:

WM. H. CAPEL, GEORGE H. STOCKBRIDGE.

6th day of April supplementing the spectrum- 

